<select name="sed_id" <?php echo $estilo; ?>>

    <?php
	
    $sql_sede = "SELECT * FROM sede ORDER BY sed_id";
    $res_sede= sql($sql_sede);

    while($linha_sede = mysql_fetch_array($res_sede)){
    ?>

    <option value="<?=$linha_sede['sed_id'];?>" <?php if($linha_sede['sed_id'] == $sed_id) { echo "selected"; } ?>><?=$linha_sede['sed_nome'];?></option>

    <?php } ?>

</select>